可编程控制器在热压机中的应用

提出一种可编程控制器（PLC）来改造热压机的例子。经改造后的热压机，采用西门子的S7－200系列PLC作为控制部件。它利用PLC的控制功能，实现热压机的自动控制，所使用的电器元件比改造前要少得多。同时，系统具有工作可靠、故障率低、维护 方便等优点，能较好提高生产效率，并降低生产成本。     

高速公路隧道监控系统PLC采集交通指示灯真状态的实施方案

本文介绍了在高速公路隧道监控系统——交通控制子系统与本地控制器子系统工作原理，详细阐述了这两个系统衔接过程中的控制与采集电路，提出了PLC采集交通指示灯假状态的设计隐患，并针对性的提出了解决方案。     

PLC在烘房烘干控制中的应用

本文介绍了烘房烘干的工艺过程及PLC在该系统中的控制应用，使系统烘干质量高，工作可靠，设置、操作简单，提高了生产效率。     

PLC在煤矿提升机控制系统的应用研究

对提升机安全运行的制动系统中的模拟量和自动调节过程进行了分析，提出了使用PLC控制提升机制动系统的观点，并结合提升机制动系统的结构，对PLC控制提升机制动系统进行了设计。     

退火炉的PLC控制系统

本文分析了球墨铸铁管退火炉的各段加热曲线的特性,对该PLC控制系统进行了配置,分析了组态王的工作原理及功能,经工厂运行实践性能良好。     

PLC过程控制的故障特点与排除措施分析

PLC是一种专门在工业环境下应用而设计的数字运算操作的电子装置,影响着工业生产及运营过程。信息化时代的发展,各企业均加大了信息力度,在过程控制中逐渐融入了信息化技术,不断优化控制系统结构的同时也不断更新工作方式。为了延长PLC控制使用寿命,提高PLC控制工作效率,PLC系统在运行中需较为全面掌握设备的消耗和故障发生点。对PLC过程控制的故障特点全面分析,探PLC过程控制的排除措施,以此提高PLC系统使用时间和工作效率。     

可编程序控制器对热压机的控制

介绍了塑钢窗热压机的结构以及PLC控制系统的设计。     

基于PLC的模糊参数自整定控制器在热压机中的应用

通过热压机液压工作原理、生产工艺分析,对系统硬件进行了配置,分析设计了模糊PID控制器,经编程在S7-300PLC环境下实现,结果证明运行效果良好.     

PLC修井机液压系统在修井中的应用

不压井作业自动化提高是当前石油生产部门的主要研究课题之一，通过自动化程度的提高可以有效降低工作人员的压力，因而文章主要对独立式不压井的修井设备进行了分析。并将PLC系统应用于修井机中，设计出了一套自动化的液压控制系统。并针对其工作原理进行了论述，最终提出了PLC控制框架以及相关系统方案。通过PLC的利用，有效提高了修井机的修井效率，并且在作业的过程中，管柱事故发生频率也大大降低，提高了生产系统的安全性以及自动化水平。     

红外线加热炉温度PID控制及优化

为了将红外线加热应用于连续退火实验,要求对红外线加热的温度进行有规律的控制·主要介绍所采用的PLC控制理论算法,包括系统辨识、比例积分微分参数整定及优化设计·通过PLC对红外线快速加热炉温度的控制,实现了对试样的快速加热和冷却及温度升降的循环控制,而且升降时间和速度可精确调整,经实际应用取得了良好的效果·     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the